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CM3 dpad wiring
#1
I am considering adding tac switches for the d-pad on my CM3 board. To do this I am thinking of drilling small holes around the pads for the dpad to secure and wire the tac switches to. Does anyone know if the PCB is multi layered? I would hate to break a trace in the middle of the board that I can't see. Additionally, does anyone know if the pads for the d-pads are wired straight to the sodimm socket or do they run through any IC's or resistors? If so that might be an alternative instead of drilling. I apologize if there is a published schematic for the PCB that I could look at to find this info, I looked around but couldn't find one. Thanks.
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#2
The Freeplay CM3 is a 4-layer board. When I get a chance, I'll try to get some more detailed info that will help.
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#3
Are you planning to use some specific buttons/switches?

All the digital buttons are wired directly to GPIO pins on the Pi CM3 (or Zero). There aren't any resistors or anything like that in-between. Furthermore, you can use any GPIO you want. You would just edit the /etc/modprobe.d/mk_arcade_joystick.conf file accordingly.

You could leave the current DPAD alone and wire up 4 tac switches deadbug style with wires running to open GPIO. The "v1.3" board has some open GPIO, but they're a bit small. If you're not using an add-on board, you could easily use GPIO 40-45 that are between the USB socket and the ABXY button area.

After investigating, I don't see a safe way to drill holes in the dpad area.
Card Fighters' Clash 2 English Translation ( http://cfc2english.blogspot.com/ )
Neo Geo Pocket Flash Cart and Linker Project ( http://www.flashmasta.com/ )
Avatar art thanks to Trev-Mun ( http://trevmun.deviantart.com/ )
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#4
(09-16-2020, 03:02 AM)Flavor Wrote: Are you planning to use some specific buttons/switches?

All the digital buttons are wired directly to GPIO pins on the Pi CM3 (or Zero).  There aren't any resistors or anything like that in-between.  Furthermore, you can use any GPIO you want.  You would just edit the /etc/modprobe.d/mk_arcade_joystick.conf file accordingly.  

You could leave the current DPAD alone and wire up 4 tac switches deadbug style with wires running to open GPIO.  The "v1.3" board has some open GPIO, but they're a bit small.  If you're not using an add-on board, you could easily use GPIO 40-45 that are between the USB socket and the ABXY button area.

After investigating, I don't see a safe way to drill holes in the dpad area.

Thanks for the quick reply. Thanks for confirming, I had a suspicion that the board was multilayered. I have some left over two pin tac switches that I used to replace the ABXY buttons with. I think I can 3D print a switch holder to keep the switches in place and deadbug mount using the 40-45 GPIO, I'm already using one of the GPIO for a rear button I mounted and remapped the hotkey to.
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#5
Let us know how it all goes. I'm definitely interested to see it.
Card Fighters' Clash 2 English Translation ( http://cfc2english.blogspot.com/ )
Neo Geo Pocket Flash Cart and Linker Project ( http://www.flashmasta.com/ )
Avatar art thanks to Trev-Mun ( http://trevmun.deviantart.com/ )
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